1. Field of the Invention
The present invention relates to a pipe joint.
2. Description of the Related Art
FIG. 24 shows an example of a conventional pipe joint used for connecting metal or resin water pipes. This pipe joint is interposed between junction pipes 1 facing each other on axis to join water-tightly, and is composed to tighten a pipe joint main body 2′ and a pair of right and left push rings 3′ by means of a clamp 4. The pipe joint main body 2′ includes a shell 2b′ formed integrally between mutually facing flange-shaped protrusion 2a′ and protrusion 2a′, and a tapered receptacle 2c′ spreading widely in the end direction of the inner peripheral side of the protrusion 2a′. The push ring 3′ has a flanged protrusion 3a′, and is disposed at both ends of the pipe joint main body 2′ disposed to leave a peripheral gap on the outer circumference of the junction pipe 1. By tightening the clamp 4, a rubber packing ring 5′ set between the pipe joint main body 2′ and each of push rings 3′ is pressed by the leading end 3b′ of the push ring 3, and is inserted into the receptacle 2c′, and is also pressed against the outer circumference of the junction pipe 1, so that the junction pipes 1 are coupled to each other (Japanese unexamined patent publication No. 2003-42359). The coupled junction pipes 1 are expandable and flexible at the junction.
Conventionally, in order to enhance the working efficiency at the site of installation, the pipe joint has been temporarily assembled. In this preliminary assembly, the rubber packing ring and other necessary parts are preliminarily position in the radial direction and axial direction. An example of temporarily assembled pipe joint is shown in FIG. 25(a). In this pipe joint, a stopping bump 13a of annular spacer 13 is engaged with a stopping recess 51a of rubber packing ring 51, and the leading end of the rubber packing ring 51 is inserted into the receptacle 2c′ of the pipe joint main body 2′, and further the clamp (not shown) of the push ring 3′ is tightened until a positioning protrusion 13b of annular spacer 13 abuts against the corner of opening edge of the receptacle 2c′ of the pipe joint main body 2′, thereby assembling temporarily (Japanese patent publication No. 3061136).
Another pipe joint without such an annular spacer is proposed, in which the pipe joint is used for temporary assembly. In the pipe joint shown in FIG. 26(a), a stopper 52c provided at base 52b of rubber packing ring 52 abuts against a receptacle peripheral outer side 2f′ of pipe joint main body 2′, and a tip 52a of rubber packing ring is provisionally stopped in receiving hole 2e′ at the inlet of receptacle 2c′. The leading end 3b′ of the push ring 3′ moved by tightening of the clamp (not shown) is fitted to the outer peripheral side 52e of the base 52b of the rubber packing ring 52, and is assembled temporarily (Japanese unexamined patent publication No. 2003-42359).
At the time of installation, the junction pipe 1 is inserted into the temporarily assembled pipe joint, and by moving the push ring 3 by tightening the clamp, as shown in FIGS. 25(b) and (c), or in FIG. 26(b) and (c), the rubber packing rings 51, 52 are tightly coupled with the receptacle 2c′ in wedge form, and are compressed to the outer circumference of the junction pipe 1, and the junction pipe 1 is joined.
As shown in FIGS. 24 to 26 an anti-slip ring 6′ is provided at the inner peripheral side of the push ring 3′, and it is engaged with the outer side of the junction pipe 1, thereby preventing its detachment. Also as shown in FIG. 24 and FIG. 27, the push ring 3′ is separated at one position in the circumferential direction, and by tightening a stopper 11, it is composed to be contracted in diameter. At the time of installation, after tightening the clamp 4, the stopper 11 is tightened to contract the diameter of the push ring 3′, and the anti-slip ring 6′ is compressed and engaged with the outer surface of the junction pipe 1, and detaching is prevented.
However, since the conventional push ring has such stopper, the shape is complicated, having a stopper boss 12 as shown in FIG. 24 and FIG. 27, and extra material and process are needed for production of push ring. Also at the time of installation, since the tightening process of stopper is needed, the working efficiency has been disturbed.